The invention relates to a method for positioning and/or guiding at least one arbitrary process head (print head) or a printing unit comprising at least one pressure nozzle for the metallization (imprinting) of thin substrates such as wafers at a defined distance above the surface of the substrate (wafer), which is to be provided on a support (paddle; printing table). The invention also relates to a device, comprising at least one print head for carrying out such a method.
A screen printing machine for the solar cell production comprising a printing unit, which can be moved up and down, and a printing table, via which a conveyor belt can be moved, wherein provision is made for a positioning device, which positions the solar cells on the conveyor belt so as to be accurately aligned to the printing unit, is known from DE 10 2006 558 A1. An adjusting device for the printing unit is not required here.
In a screen printing method known from DE 692 30 099 T2, a substrate, which is to be imprinted, is fixed on a printing table, wherein the substrate and the screen, which is used, are provided with reference marks. The position of the reference marks of the substrate applied on the printing table is optically captured and stored by means of an observation unit, which is positioned above the printing table. In response to the positioning of the screen above the substrate, which is to be imprinted, the position of the reference marks of the screen and the relative position of the screen to the substrate on the printing table is determined thereby and the reference marks on the substrate and on the screen are aligned by means of a corresponding correction of the position of the screen.